Agreed ... using a local professional would be wise ... you have to fill in and file a 8594 form that both parties agree on and shut down the business if needed ... these things can be compicated if you don't know what you need to do.
https://www.irs.gov/newsroom/what-if-i-close-my-own-business
https://www.irs.gov/pub/irs-pdf/f8594.pdf
